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Soybean diseases trekking north

Frogeye leaf spot continues to migrate north.

BASF technical service rep Derek Cottrill says the soybean disease, which was identified in Watertown, South Dakota a year ago, was discovered further north and west earlier this month.

“We found it in a plot in Northville, South Dakota Tuesday. Wouldn’t expect that to happen, but we’re getting these milder temperatures with plenty of moisture we usually don’t have.”

Early symptoms of Frogeye leaf spot include dark lesions on younger soybean leaves.

He tells Brownfield another soybean disease that tends to thrive when temps are mild and conditions are wet is white mold.

“White mold the last couple years in the northern half of the state has become more and more of a challenge. This year is going to be no different because when that crop is maturing and (white mold) is a problem during the flowering stage, that’s going to happen generally later this year with the later-planted crop.”

He says both white mold and Frogeye can be managed with a fungicide.

Brownfield spoke to Cottrill at the Ag Phd Field Day near Sioux Falls, South Dakota.